L-acyloxy-z-alkylbtjtadiene-l



Patented Dec. 9, 1947 1-ACYLOXY-Z-ALKYLBUTADIENE- 1,3 COMPOUNDS JosephB. Dickey, Rochester, N. Y., and Clarence G. Stuckwisch, Wichita, Kans.,assignors to Eastman Kodak Company, Rochester, N. Y., a corporation ofNew Jersey No Drawing. Application February 9, 1946, Serial No. 646,709

Claims. (Cl. 260- 49;)

This invention relates to l-acyloxy-Z-alkylbutadiene-1,3 compounds andto a method for their preparation. More specifically, it relates tocliene compounds of the general formula:

wherein R represents an alkyl group, for example, methyl, ethyl, propyl,butyl, amyl, isopr-opyl, and R1 represents an alkyl group, analkoxyalkyl group such as methoxymethyl, ethoxymethyl, a halogensubstituted alkyl group, for example, monochloromethyl, monobromomethyl,dichloromethyl, trichloromethyl, trifluoromethyl, and groups such asfuryl, tetrahydrofurfuryl, naphthenyl, aminosulfone-or alkylsulfonegroups.

The compounds above defined are valuable intermediates for chemicalreactions of transformation and polymerization reactions. Thepreparation of such polymers are described in copending application, inthe name of J. B. Dickey, N. J. Bowman and C. G. Stuckwisch, Serial No.646,708, filed of even date herewith.

In the preparation of the compounds of our invention, there can beemployed as intermediate compounds unsaturated aldehydes of the formula:

- RzCH=CCHO fir-R3 wherein R2 represents hydrogen or an alkyl group andR3 represents an alkyl group, the specific aldehyde being reacted withan isopropenyl compound such as isopropenyl acetate or with an aliphaticacid anhydride, in the presence of a basic salt including for the mostpart an alkali metal salt of the reaction acid. Cupric acetate insmaller amount is employed as a polymerization inhibitor. The proportionof reactants can be present in varying amounts, but preferably onemolecular proportion of the aldehyde is reacted with one or moremolecular proportions of the aliphatic acid anhydride, in the presenceof about 0.5 to 3 molecular proportions of the basic material consistingin greater proportion of an alkali metal salt of the aliphatic acid. Theunsaturated aldehyde can be, for example, an alphaor betasubstitutedacrolein or an alpha-substituted crotonaldehyde prepared, in general, asdescribed for alpha-methyl crotonaldehyde in the Canadian Journal ofResearch, 6 284 (1932), and alphaethyl acrolein, Annalen 434 145 (1923).The acid anhydride can be, for example, acetic, propionic, butyric,valeric, palmitic, furoic, tetrahydrofuroic, methoxyacetic,phenylacetic, succinic,

chloroacetic, fluoroacetic, trichloroacetic, di-

fluoroacetic, benzoic, abietic, aminosulfonacetic pressure.

or methylsulfonacetic anhydride.

It is, accordingly, an object of this invention to provide new lacyloxy-2-alkylbutadiene-1,3 compounds. Another object is to provide amethod for preparing the same. Other objects will become apparenthereinafter.

The following examples will serve to illustrate our new compounds andthe manner of obtaining the same.

Example I. 1-acetory-2-methyZbutadiene-1,3

' 222 grams of alpha-ethyl acrolein, 382 grams of acetic anhydride, 174grams of sodium acetate and 2 grams of cuprie acetate were refluxed withstirring for 12 hours and then poured into water and stirred 4 hours.The oily layer obtained was separated and fractionated at reducedpressure. The 1-acetoxy-2-methyl4,3-butadiene thus obtained had aboiling point of 92 C. at 40 mm. The analysis gave 66.21 per cent byweight of carbon, 7.45 per cent by weight of hydrogen and 33.5 per centby weight acetyl as compared to calculated theoretical of 66.67 per centcarbon, 7.93 per cent hydrogen and 34.1 per cent acetyl. In place ofaIpha-ethyl acrolein in the above example, there can be substitutedalphamethyl crotonaldehyde.

Example I I. I-propz'onomy-Z-methyl butadiene 222 grams of alpha-ethylacrolein, 468 grams of propionic anhydride, 204 grams of anhydroussodium propionate and 2 grams of cupric acetate were refluxed withstirring for 12 hours and then poured into water and stirred for 8hours. The oily layer obtained was separated and fractionated at reducedpressure. The product, l-propionoxy-2-methyl-1,S-butadiene, boiled at C.at 40 mm. pressure.

Example III. 1-trifluoroacetory-Z-methyl butadime-1,3

222 grams of alpha-ethyl acrolein, 682 grams of trifiuoroaceticanhydride, 411 grams of sodium trifluoroacetate and 2 parts of cupricacetate were refluxed with stirring for 8 hours and then poured intowater and stirred for 4 hours. The oily layer obtained was separated andfractionated at reduced pressure. The product. l-trifiuoroacetoxy-2-methyl-1,3-butadiene, boiled at 78 C., at 40 mm. pressure.

63 alpha-ethyl-beta-propylacrolein, 50 grams of isopropenyl acetate and6 drops of sulfuric acid were heated on a steam bath with a take offreflux condenser. After about 30 c. c. of acetone'had distilled over,the acid was neutralized, and the product distilled over under reducedpressure. The 1-acetoxy-Z-butyl-butadiene-1,3 boiled at 101-105" C. at22 mm. pressure.

Other 1-acyloxy-2-alkylbutadiene-1,3 compounds were also prepared by theprocedure of the above examples includingl-acetoxy-Z-ethylbutadiene-l,3, 1-acetoxy-2-propylbutadiene-1,3,l-acetoxy-2-amylbutadiene-1,3, 1-acetoxy-2-isopropylbutadiene,1-m'ethoxyacetoxy-2-methylbutacliene-1,3,l-ethoxyacetoxy-Z-methylbutadiene- 1,3,1-chloroacetoxy-2-butylbutadiene-1,3,l-bromoacetoxy-2-methylbutadiene-1,3,l-dichloroacetoxy-2-methylbutadiene-1,3, l-trichloroacetoxy-Z-methylbutadiene-LS, 1-difiuoroacetoxy-2-methylbutadiene-1,3,1-difluorachloroacetoxy-2-ethyle butadiene-1,3,1-tetrahydrofuroyloXy-2-propylbutadiene-1 ,3,1-naphthenoyloxy-2-methylbutadiene-1,3,1-amlnosulfonacetoxy-Z-methylbutadiene-1,3,1-methylsulfonacetoxy-2-methylbutadi ene-1,3, and similar kinds ofcompounds.

What we claim is: i

1. The process which comprises reacting an aldehyde having the formula:

wherein R2 represents a member selected from' the group consisting of ahydrogen atom and an alkyl group having from 1 to 3 carbon atoms, withthe acid anhydride of a saturated fatty acid of from 2 to 4 carbonatoms, in the presence of an alkali metal salt of the fatty acid.

2. The process which comprises reacting an aldehyde having the formula:

with the acid anhydride of a saturated fatty acid of from 2 to 4 carbonatoms, in the presence of an alkali metal salt'of the fatty acid, andcupric acetate.

3. The process which comprises reacting alphaethylacrolein with aceticanhydride, in the presence of sodium acetate and a smaller portion ofcupric acetate. Y

4. The process which comprises reacting alphaethyl acrolein withproplonic anhydride, in the presence of sodium propionate and cupricacetate.

5. The process which comprises reacting alphaethyl acrolein withtrifiuoroacetic anhydride, in the presence of sodium trifiuoroacetateand cupric acetate.

JOSEPH B. DICKEY. CLARENCE G. STUCKWISCH.

' REFERENCES CITED The following references are of record in the file ofthis patent.

UNITED STATES PATENTS Number Country Date 2,021,698 Perkins Nov. 19,1935 2,073,363 Caruthers et al Mar. 9, 1937 2,215,180 Kaufler Sept. 17,1940 FOREIGN PATENTS Number Name Date 723,773 Germany Aug. 10, 1942740,367 Germany Oct. 19, 1943

